Posts

Erosion and Sediment Control Tip #32

Image
  There are many Sediment Control Practices that require the captured sediment to be removed and properly disposed of when ½ of the sediment storage volume has been reached.  First, if you are having to deal with sediment removal on your construction site, you should look upslope and fix the erosion control methods and practices.  However, if you must remove sediment, do so without destroying the sediment control practice. Where is the location for placement of the sediment and how should it be “properly” disposed of?  Most likely the sediment will be saturated.  This requires the material to dry out somewhat before it can be stabilized.  Locate a good area on the jobsite.  Preferably a site with good vegetation downslope and not near a receiving stream.  If there is no vegetation that could serve as a grass filter, then you’ll probably need to install a silt fence to control the runoff. Stack the removed sediment as much as it will stack and let it drain. As soon as it is drained to a

Erosion and Sediment Control Tip #31

Image
  Many of the Erosion Control Products like Rolled Erosion Control Blankets, Turf Reinforcement Mats, tied concrete block mats, and other manufactured products rely on vegetation for permanent stabilization.  This means that the soil underneath these products must be of the quality to support vegetation.  Eric Marsal of the American Excelsior Company and John Slupeki of Motz Enterprises Inc. (Flexamat) have helped me develop the following list of things to remember about getting vegetation established for these erosion control  products:   Take a soil test to know the lime and fertilizer requirements. Eliminate compaction problems.  Roots can’t penetrate compacted layers. Caution: DON’T rip the soil in the direction of flowing surface water.  This can result in erosion.  Rip or disc the soil perpendicular to water flow if possible. Rototilling can be done in either direction. Correct a low pH by INCORPORATING lime.  Acid soils need lime to rais

Erosion and Sediment Control Tip #30

Image
  You have often heard us talk that an Erosion and Sediment Control Plan for a construction site should be “Site Specific”.  That’s because every site (even a small home site lot) is a little different from the other sites.  So designers should be careful and not use what I call “cookie cutter” plans for erosion and sediment control.  While the plans can be similar and have some of the same features, the plans should meet the requirements for the specific location. Make sure your plan is ON TARGET.   Perry L Oakes, PE Erosion and Sediment Control Program Coordinator AL Soil and Water Conservation Committee

Erosion and Sediment Control Tip # 29

Image
  Today’s erosion and sediment control tip is provided by Barry Fagan of Volkert, Inc.   Delay and Limitation of Soil Disturbance as a Best Management Practice   The product of the Revised Universal Soil Loss Equation (RUSLE), which can be used to estimate soil loss from a particular slope, is given in units of tons per acre per year (t/ac/yr.), or mass per area of disturbance per duration of disturbance. To cause the amount of sediment trying to leave a slope to be reduced, one must also reduce the area and/or the duration of disturbance. Both are achievable on most construction projects.   One of the most effective practices available for the management of construction stormwater is the protection and retention of established vegetation and soil cover. The next most effective practice may be the effort to return to a state of stabilization as soon as possible.   Delaying soil disturbance can be achieved by evaluating the scope and sequence of the work and requiring or

Erosion and Sediment Control Tip # 28

Image
  Pipes that go through an embankment (Sediment Basin, Stormwater Detention Basin, and Drop Structures) often require seepage control to be placed on the outside of the pipe to stop what is referred to as “soil piping”.  Soil Piping is the slow removal of soil particles on the outside surface of the pipe and over time creates a tunnel (or pipe) from the outlet end of the pipe to the entrance end of the pipe.  Anti-seep collars have historically been used to help with this issue.  However, filter diaphragms have been recognized as superior to anti-seep collars as a seepage control measure. A filter diaphragm is a designed zone of filter material (usually well-graded, clean sand) constructed around a conduit to intercept seepage and safely discharge the water to the outlet end of the pipe through a graded filter (without carrying soil particles). For you designers, check out this NRCS reference document.   https://directives.sc.egov.usda.gov/OpenNonWebContent.aspx?content=17751.wba

Erosion and Sediment Control Tip #27

Image
  I’m going to get on my soapbox a little this time and discuss mowing maintenance of vegetation.  A lot of the roadside and large area mowing maintenance is done with tractors equipped with lugged pneumatic tires. Lugged pneumatic tires were first developed in the 30’s primarily to get better traction, better fuel economy, and more power in a plowed farm field.  Pneumatic tractor tires are very advanced today with more ground contact to reduce compaction problems and increase traction. While lugs can create some soil compaction issues, my beef is the use of these tires in challenging locations like steep vegetated slopes and wet areas.  Anywhere the tractor tire can slip or spin, the vegetation is often destroyed.  This is a common case on roadside slopes.  If the conditions are too severe to keep the tires from slipping, something else should be used to maintain the vegetative cover on the site. Less frequent mowing, using tires that don’t slip, using vegetation that requires less or

Erosion and Sediment Control Tip #26

Image
  Most Erosion Control Blankets use some type of netting to bind and hold products so the blankets stay together, are more easily handled, and keep the mulch material in place to do its job.  Most ECB companies have wildlife friendly netting available to ensure the wildlife in the area are not needlessly harmed.  So, if you plan the use of ECB’s or netting of any type on your project, consider the use of wildlife friendly netting. I reached out to Eric Marsal of the American Excelsior Company to provide the following insight: Most blanket companies now provide netting that is considered Wildlife Friendly.  It is best that Wildlife Friendly netting be 100% biodegradable. Wildlife Friendly netting should be loosely wrapped at the junctions (seam) to allow the netting to stretch when stress is applied to it, thus greatly reducing entanglements (picture). When it can be used, a net-free blanket would be the best alternative. One final note to me